-----Original Message-----
From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Ni, Ray
Sent: Tuesday, August 11, 2020 4:06 PM
To: Gao, Zhichao <zhichao.gao@...>; devel@edk2.groups.io
Cc: Wang, Jian J <jian.j.wang@...>; Wu, Hao A <hao.a.wu@...>;
Gary Lin <glin@...>; Andrew Fish <afish@...>
Subject: Re: [edk2-devel] [PATCH 2/3] MdeModulePkg/PartitionDxe: Remove
the check for special MBR

Zhichao,
Can you please just revert the fix you recently added?

-----Original Message-----
From: Gao, Zhichao <zhichao.gao@...>
Sent: Tuesday, August 11, 2020 2:43 PM
To: devel@edk2.groups.io
Cc: Wang, Jian J <jian.j.wang@...>; Wu, Hao A
<hao.a.wu@...>; Ni, Ray <ray.ni@...>; Gary Lin
<glin@...>; Andrew Fish <afish@...>
Subject: [PATCH 2/3] MdeModulePkg/PartitionDxe: Remove the check for
special MBR

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2823

Follow the spec definition, the ISO 9660 (and UDF) would be checked
before the MBR. So it is not required to skip such MBR talbe that
contian the entire block device.

Cc: Jian J Wang <jian.j.wang@...>
Cc: Hao A Wu <hao.a.wu@...>
Cc: Ray Ni <ray.ni@...>
Cc: Gary Lin <glin@...>
Cc: Andrew Fish <afish@...>
Signed-off-by: Zhichao Gao <zhichao.gao@...>
---
.../Universal/Disk/PartitionDxe/Mbr.c | 19 -------------------
1 file changed, 19 deletions(-)

diff --git a/MdeModulePkg/Universal/Disk/PartitionDxe/Mbr.c
b/MdeModulePkg/Universal/Disk/PartitionDxe/Mbr.c
index 3830af1ea7..822bf03e92 100644
--- a/MdeModulePkg/Universal/Disk/PartitionDxe/Mbr.c
+++ b/MdeModulePkg/Universal/Disk/PartitionDxe/Mbr.c
@@ -55,25 +55,6 @@ PartitionValidMbr (
StartingLBA = UNPACK_UINT32 (Mbr->Partition[Index1].StartingLBA);
SizeInLBA = UNPACK_UINT32 (Mbr->Partition[Index1].SizeInLBA);

- //
- // If the MBR with partition entry covering the ENTIRE disk, i.e. start at

LBA0

- // with whole disk size, we treat it as an invalid MBR partition.
- //
- if ((StartingLBA == 0) &&
- (SizeInLBA == (LastLba + 1))) {
- //
- // Refer to the

http://manpages.ubuntu.com/manpages/bionic/man8/mkudffs.8.html

- // "WHOLE DISK VS PARTITION"
- // Some linux ISOs may put the MBR table in the first 512 bytes for

compatibility reasons with Windows.

- // Linux kernel ignores MBR table if contains partition which starts at

sector 0.

- // Skip it because we don't have the partition check for UDF(El Torito

compatible).

- // It would continue to do the whole disk check in the UDF routine.
- //
- DEBUG ((DEBUG_INFO, "PartitionValidMbr: MBR table has partition entry

covering the ENTIRE disk. Don't treat it as a

valid MBR.\n"));
-
- return FALSE;
- }
-
if (Mbr->Partition[Index1].OSIndicator == 0x00 || SizeInLBA == 0) {
continue;
}
--
2.21.0.windows.1